An Etymological Dictionary of Astronomy and Astrophysics

A small → dwarf irregular galaxy belonging to the → Local Group, which is located in the constellation → Cassiopeia.
IC 10 is about 2.3 million light-years distant and about 5,000 light-years across. With an absolute B magnitude of -16.5, IC 10 has an integrated luminosity that is comparable to that of the → Small Magellanic Cloud, although it is considerably smaller. Its → metallicity is roughly a factor of 2 higher than that of the SMC and in the same proportion smaller than → LMC’s. Compared to other Local Group galaxies, IC 10 has a large population of newly formed stars that are massive and intrinsically very bright, especially → Wolf-Rayet stars. Its W-R star density is larger than those of the LMC and SMC. Moreover, the relative number of known → WC to → WN type Wolf-Rayet stars is unusually high, which is unexpected for IC 10’s metallicity. IC 10 is also known to be unusual in having → H I gas that extends about 7 times the optical dimensions of the galaxy. IC 10 is the nearest example of a → starburst galaxy. IC 10 was discovered by the American astronomer Lewis A. Swift (1820-1913) in 1887.

See also: Number 10 in the → Index Catalogue.

A → dwarf irregular galaxy (also called Caldwell 51) located in the constellation → Cetus. IC 1613 is a member of the → Local Group of galaxies and has a → morphological classification of IBm (Irregular Barred, → Magellanic type galaxy). IC 1613 has a very → low surface brightness and a very low → dust content. It lies just over 2.38 &plusmn 0.07 million → light-years
away from us. IC 1613’s distance is known to a remarkably high precision, partly due to the unusually low levels of dust lying both within the galaxy and along the line of sight from the → Milky Way. Moreover, the galaxy hosts a number of → Cepheid variables and → RR Lyrae variables which can be used to precisely determine distances. It was discovered by Max Wolf in 1906.

See also: IC, short for → Index Catalogue.

A bright → emission nebula running north to south near → Alnitak, the eastern star of → Orion’s Belt. It is the bright background nebula against which the famous dark region called the → Horsehead Nebula stands out.

See also: IC, → Index Catalogue.

1. The solid form of water; it is found in the atmosphere as snow crystals, hail, ice pellets, etc., and on the Earth’s surface in forms such as frost, rime, glaze, glacier ice, etc.
   
2. The solid, frozen form of gases in cold astronomical objects.

Etymology (EN): Ice, from O.E. is “ice,” from P.Gmc. *isa-; cf. O.N. iss, O.Fris. is, Du. ijs, Ger. Eis. Cognate with Pers. yax, as below.

Etymology (PE): Yax, from Av. aexa- “ice, frost,” isav-, isu- “icy, chilly;” cf. Sarikoli (Pamir dialect) īš “cold;”
P.Gmc. *isa-, as above.

Meteo.: The process by which a layer of ice builds up on solid objects that are exposed to freezing precipitation or to supercooled fog or cloud droplets.

See also: → ice; → accretion.

A major interval of geologic time during which extensive ice sheets (continental → glaciers) formed over many parts of the world.

There have been at least five significant ice ages in Earth’s history, with approximately a dozen epochs of glacial expansion occurring in the past 1 million years. The last one ran from about 75,000 to 15,000 years ago.

See also: → ice; → age.

A tiny particle of ice within which → water molecules are all lined up in a precise → crystalline structure. Ice crystals come in various shapes including needles, → dendrites, hexagonal columns, and → platelet. If the temperature decreases the water molecules can crystallize, arranging themselves around the suspended impurities such as dust particles. See also → snow crystal.

See also: → ice; → crystal.

A member of the lesser mass group of → gas giants. Ice giants contain a higher quantity of materials that form ices at low temperatures, such as → water, → methane, and → ammonia. There are two ice giants in the Solar System, → Uranus and → Neptune.

See also: → ice; → giant.

A building for storing ice throughout the year, mainly used prior to the invention of the refrigerator.

Etymology (EN): → ice; → house.

Etymology (PE): Yaxcâl, literally “a pit of ice,” but “any place or vessel in which ice is kept,”
from yax, → ice, + câl “pit, → hole.”

The temperature at which a mixture of air-saturated pure water and pure ice may exist in equilibrium at a pressure of one standard atmosphere.

See also: → ice; → point.

A large mass of floating or stranded ice that has broken away from a glacier; usually more than 5 m above sea level.

Etymology (EN): Iceberg, half Anglicization, half adoption of
Du. ijsberg “ice mountain,” from ijs, → ice,

• berg “mountain” (cf. Ger. Eisberg, Sw. isberg), from P.Gmc. *bergaz; cf. M.H.G. berc, O.H.G. berg “mountain;” cognate with Pers. boland, borz, berg, as below; PIE base *bheregh- “high, elevated.”

Etymology (PE): Yaxberg, from yax, → ice,

• berg “mountain, hill,” in Laki dialect, related to Pers. boland “high,” variants bâlâ “up, above, high, elevated, height,” borz “height, magnitude” (it occurs also in the name of the mountain chain Alborz),
  Laki dialect berg “hill, mountain;” Mid.Pers. buland “high;” O.Pers. baršan- “height;” Av. barəz- “high, mount,” barezan- “height;” cf. Skt. bhrant- “high;” L. fortis “strong” (Fr. & E. force); O.E. burg, burh “castle, fortified place,” from P.Gmc. *burgs “fortress;” Ger. Burg “castle,” Goth. baurgs “city,” E. burg, borough, Fr. bourgeois, bourgeoisie, faubourg); PIE base *bhergh- “high.”
  

1. An image; a representation.
   

   2. A representation or picture of a sacred or sanctified Christian personage, traditionally used and venerated in the Eastern Church.
      

   3. A person or thing regarded as a symbol of a belief, nation, community, or cultural movement.
      

   4. Computers: A pictorial representation of a facility available on a computer system, that enables the facility to be activated by means of a screen cursor rather than by a textual instruction (TheFreeDictionary.com).

Etymology (EN): From Gk. eikon “likeness, image, portrait; a semblance;” in philosophy, “an image in the mind,” related to eikenai “be like, look like,” from PIE *weik- “to be like.”

Etymology (PE): Zodiš, variant of Mid.Pers. uzdês “icon; image; idol,” from uz-, → ex-, + dês, Av. daēs- “to show;” cognate with Gk. deiknumai “to show;” L. dicere “to utter, say, proclaim;” N.H.G. zeigen “to say;” O.E. têon “to annoince;” PIE
*deik- “to show, point out; announce.”

Made of, covered with, or containing → ice.

See also: → ice + an English suffix of adjectives denoting “characterized by or inclined to.”